/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.runtime.iterative.concurrent;

import org.apache.flink.runtime.iterative.task.IterationHeadTask;
import org.apache.flink.runtime.iterative.task.IterationTailTask;

import java.util.concurrent.CountDownLatch;

/**
 * Resettable barrier to synchronize the
 * {@link IterationHeadTask} and
 * the {@link IterationTailTask} in case of
 * iterations that contain a separate solution set tail.
 */
public class SolutionSetUpdateBarrier {

	private CountDownLatch latch;

	public void setup() {
		latch = new CountDownLatch(1);
	}

	/**
	 * Waits (blocking) on barrier.
	 *
	 * @throws InterruptedException
	 */
	public void waitForSolutionSetUpdate() throws InterruptedException {
		latch.await();
	}

	/**
	 * Releases the waiting thread.
	 */
	public void notifySolutionSetUpdate() {
		latch.countDown();
	}
}
